This invention relates generally to aircraft glide slope control apparatus and particularly to an acousto-optic communication system between an approaching aircraft and base landing facilities such as an aircraft carrier for enhancing the control and safety of aircraft landings.
Successful aircraft landings, particularly those maneuvers involving a landing between an approaching aircraft and a seagoing landing facility such as an aircraft carrier, necessitate the highest degree of safety and control in order to insure maximum protection for personnel and equipment. The control and guidance of an aircraft approaching a carrier is generally assisted by a landing signal officer (LSO) placed on the carrier deck and who has both visual and radio contact with the approaching aircraft. Upon approaching the carrier, the oncoming aircraft begins to assume a predetermined glide slope pattern which defines the path along which the approaching aircraft can most safely and accurately land on the carrier deck. The pilot of the aircraft receives glide slope correction information such as engine power level, altitude and turning commands from the LSO aboard the carrier during the time the aircraft is in the glide slope path. Historically, radio communications between the pilot and the LSO have provided the basic method for communicating glide slope commands between the carrier and aircraft. One important operating parameter indicative of a proper response to a pilot initiated directive is the engine noise produced by the aircraft compressor or pistons and the deviations in levels of the noise as sensed by the pilot in response to the control change. These changes in engine noise are continuously monitored by the pilot because of the pilot's proximity to the source of the noise and thus provide an added degree of confidence to the pilot in confirming engine response to pilot command. The benefit of this in-built aircraft performance monitoring system, however, is not available to the LSO positioned on the carrier deck some distance from the approaching aircraft. The capability of monitoring engine noise as an acoustic sensation would enable the landing signal officer to sense the power level and pitch of the aircraft engine thereby to confirm if the engine is properly responding to glide slope signals communicated from the LSO to the pilot and thus add an additional measure of safety and accuracy to successful aircraft carrier landings.